zero love yuuki and he wants yuuki to stay as the way she is...... but kaname know yuuki pretty well and love her soo much but still.............. zero dont want yuuki to be a vampire but kaname gave back her memories and she is already a full blood................... hmmm................... even if it hurts kaname and yuuki are the best couple....... (huhuhuhuh kaname senpai TT_TT)

Kaname X Yuki Hands down. Technically they aren't siblings. She was born for him but only took the Kuran name. I dont' know how to explain it any better. They are just soooooo kawaii together. At least I think so.

yuuki and kanamei will tell u the real thingif u read this u will know it

Zero can sense that Yuki is a pureblood and aims his "Bloody Rose" at her
She cares deeply about Zero, many times having put her life on the line to protect him, however it is unclear how she feels for him romantically

It was revealed in chapter 35 that she is the hidden daughter of the Kuran family, a family of pureblood-vampires. She and Kaname are siblings and were engaged. She does have vampire powers as well, as this was witnessed in chapter 36. As Yuki was getting over the shock of her parents deaths to save her, she accidentally made cracks in the window.
Before her memory loss, her parents kept her confined in a well-furnished underground chamber, preventing other vampires from finding out about her. She is said to be the Kuran Princess of the pure blood royal family of Kurans. The Kurans are said to be the rulers of all of the pure bloods and regular vampires.
Zero is a vampire hunter with an excellent lineage being at the same time a vampire himself. And thanks to having taken blood of three purebloods, Yuki, Kaname, and Shizuka (since Kaname drank Shizuka's blood) Zero will become the most powerful hunter and the only one capable of killing Rido - the main antagonist of the story.
At the end of chapter 39 his brother Ichiru shoots Zero through the shoulder with the "Bloody Rose", Zero's vampire killing gun. This was done to force Zero to drink his blood, in order to regain his strength. Before Ichiru came to the basement he had been mortally wounded by Rido. Knowing that his death was near, he decided to give his blood to Zero, saying that thanks to that "the thing inside [Zero's] body can be treated". After much resistance, Zero finally gave in and drank Ichiru's blood and escaped from the basement.
It has been revealed in Chapter 38 that Haruka and Juuri Kuran had a son, but his soul was killed by Rido Kuran and Kaname's soul was put into his body. Kaname was the ancestor of the Kuran Family thus resurrected by Rido from the grave, who became his "master" thus making him unable to kill Rido. (This is comparable to the relationship between Shizuka Hiou and Zero). Yuki and Kaname were planned to marry as children, following the example of Juuri and Haruka who were also brother and sister and married
Since he is the head of the Kuran clan he is said to be the Kuran king but then it is changed after Rido is said to be the real head of the Kuran family.